X17online photographers spotted Britney being driven by her bodyguard as she sat in the passenger seat, followed by another two cars.

Britney's children were not seen in the car with her, but it's possible they could be the reason for her trip to the hospital.

UPDATE: Photogs say that Britney walked into the children's wing of the hospital. We have pix coming soon...

UPDATE 2: Britney arrived at UCLA Medical Center's Mattel Children's Hospital
with two cars following her and a police escort which was pre-planned. The caravan of cars didn't appear to be moving in a way that would suggest there was an emergency. The whole thing started around noon PT today when the three cars left Spears' Calabasas home, heading for Westwood.